Primary Investigator: Jeffrey Strock
Co-investigators: Satoshi Ishii, Hao Wang
Partners: Minnesota Drainage Viewers Association, I&S Group, Inc. (ISG), Minnesota Department of Agriculture, Sand County Foundation, and Natural Resources Conservation Service of the USDA
Problem: Drainage ditches on agricultural land improve field drainage efficiency by removing excess water quickly. However, they also carry nitrogen and phosphorus, with little to no time to react, be bound, or absorbed by healthy soil or vegetation. These ditches often empty into nearby streams and rivers, to the detriment of local and downstream ecosystems.
Solution: If drainage ditches were designed to behave more like natural wetlands (chemically, biologically, and microbiologically), they could remove higher levels of nitrogen from field runoff, both through denitrification and plant uptake. Strock and his team will engineer and install low-grade weirs to decrease flow velocity and enhance nitrogen removal. Their lab-based project will also analyze biological and microbial communities to optimize the nitrogen uptake within their low-grade weir design.
Impact: Each year roughly 60 million pounds of nitrogen flows through drainage ditches leading to the Minnesota River. Improving the performance of drainage ditches to remove more nitrate offers a low-cost solution to one of Minnesota’s most persistent environmental challenges.